Each unit cell in some conventional fuel cell stacks is electrically connected to a separator itself or to a separate external terminal that is connected to a separator to generate electrical energy having a predetermined potential difference.
However, separators of a unit cell in such a conventional stack of a fuel cell are made of graphite or carbon composite, and thus, fabrication processes of the separators are very complicated. Therefore, the cost of fabrication is very high and unfavorable from an economical view.
A conventional stack of a fuel cell also generates a predetermined amount of heat in each unit cell during generation of electricity through a reaction of hydrogen or a fuel and oxygen. When such heat exceeds the appropriate temperature range, the performance of the MEA is deteriorated and stability of the unit cell cannot be ensured, resulting in damage of the unit cell in some serious cases.